The need for better methods for disposal of waste products has long existed. Society now recognizes the need to handle waste products in an environmentally sound manner that avoids building landfills and creating air or water pollution. Further, carbonaceous material may yield commercially desirable products. The concept of using molten metal, including lead, for the thermal conversion of organic matter into useful products is generally known. U.S. Pat. No. 2,450,550 to Stamm discloses distillation of granular wood or coal by submerging the granules in a molten metal bath and passing the granules through the bath, sandwiched between two endless screens. U.S. Pat. No. 3,977,960 to Stout et al. discloses thermal conversion of crushed oil shale into useful products in a chamber containing molten metal or salt in the absence of air, and the use of recovered oil in air sealing means (column 4, line 19). U.S. Pat. No. 5,085,738 to Harris et al. discloses thermal conversion of organic wastes, including vehicle tires, into useful products in a chamber containing molten lead, in the absence of air, utilizing gravity rather than a container or the like to convey the wastes through the molten lead. U.S. Pat. No. 5,693,188 to Donnohue et al. discloses thermal conversion of organic wastes, including vehicle tires and plastics, into useful products in an elongated chamber containing molten lead, in the absence of air, utilizing an auger to convey the wastes through the molten lead. U.S. Pat. No. 5,605,551 to Scott et al. discloses a process for thermal conversion of biomass such as wood to liquids by pyrolysis in a fluidized bed in which the conveying gas contains low and carefully controlled amounts of oxygen. U.S. Pat. No. 5,584,970 to Schmalfeld et al. discloses a process for thermal conversion of biomass such as wood to charcoal, the process involves drying the wood in a first flow of hot gas and then carbonizing the wood in a second flow of hot gas.
Throughout the world, there are millions of tons of wood scrap waiting for a reasonable way of recycling. Actual utilization of the wood scrap in the industrialized countries are:
1) Combustion in furnaces to produce electric power and steam. PA0 2) Conglomeration to produce low quality dirty wood, tools or furniture. PA0 3) Reforming of pallets. PA0 4) Production of wood-dust for drying purposes. PA0 5) Recovery of cellulose raw materials. PA0 6) Production of coke carbon by pyrolysis.
The prior art has not suggested a commercially viable, continuous processing method and apparatus for thermal conversion in the absence of oxygen of scrap wood to produce commercially desirable products.